Swansea Coroner's Office has told ITV News that further tests will now be carried out on Gareth Colfer-Williams, which are expected to take six to eight weeks.
His family have raised questions about the medical care he received in the days before his death.
More top news
Andrew Price joins South Wales Caving Club to venture into the deepest cave in the UK
Any drizzle this afternoon will subside to leave a largely dry evening. Clearer skies in the north overnight.
Police were called to several Tesco stores in Wales to deal with chaos at midnight. Huge numbers hunted for bargains in shops and online.